NAME Ussurithyrites
AGE    AGE span:  mya
K&J CLASSIFICATION (2000) Ascomycetes, Microthyriales.
FIGURE(S)
FIGURE REFERENCE
SPECIES, AUTHORITY Ussurithyrites Krassilov 1967, p. 94.
LOCATION
ORIG DESCRIPTION* ORIGINAL DIAGNOSIS: Thyriothecia without free mycelium, of oval shape, with a large oval ostiole in the central region, consisting of hyphae that spread fan-like from one pole of the oval stroma and form a paraplectenchymatous membrane. [Jansonius & Hills (1990), card no. 4801.]

Monotypic.
COMMENTS* The described thyriothecia probably belong to fungi from the family of Microthyriaceae, as they are composed of hyphae that are radially arranged. However, Microthyriaceae representatives have thyriothecia growing in all directions, and [from] a group of cells appearing in the center of fruiting body (or displaced slightly owing to irregular growth in various directions); hyphae grow concentrically in all directions. The specimens in question have a scutellum formed by hyphae that grow in one direction and are fan-shaped from the bases, within limits of 45-60 degrees. The ostiole is formed by destruction of the central tissue that is its oldest part, as is common in Microthyriaceae. These features distinguish the described forms from the known fossils of fungi. We believe it possible that they belong not to Microthyriaceae, but to Hemisphaeriaceae. One of the subfamilies of this family, Dictyopeltinae Theissen, has thyriothecia with a reticulate structure and no free mycelium (Stevens & Manter, 1925). Fossil representatives of Hemisphaeriaceae were described by Cookson under the name Plochmopeltinites and differ from Ussurithyrites in the presence of free mycelium and in the prosoplectenchymatous structure of the thyriothecia.
PUBLICATION REFERENCE Krassilov VA. 1967. Early Cretaceous flora of the southern Primorsk and its significance for the stratigraphy (in Russian); Academy of Sciences of the USSR Siberian Branch, Far East Geological Institute, Moscow, 264 p.

Jansonius J, Hills LV. 1990. Genera file of fossil spores - supplement 10; Special Publication, Department of Geology, University of Calgary, cards 4576-4811.
K&J REMARKS
TYPE TYPE: Ussurithyrites araucariodendri Krassilov 1967, p. 94, pl. 2, fig. 1.
ALL NAMES (Including synonyms) Ussurithyrites;
SERIAL NUMBER 1765
PUBLIC COMMENTS
 *For source, see Publication Reference.